Sniffing glue

A reader writes:

How toxic is superglue?

All I really know about it is that it's technically called "cyanoacrylate", but the "cyano" part makes me nervous. The last episode of Mythbusters I saw had them sticking stuff to other stuff with superglue (which they called "super adhesive" for some reason) and they were wearing gas masks while doing it.

Am I endangering my health if I superglue a teacup together without lots of ventilation? My son's just now started building model airplanes and tends to stare so close at the model I'm expecting him to stick a propellor to his nose soon; is HE going to be poisoned too?!


At some point in the next few thousand words I may answer your question, Eva. You know how it is with me.

The magic acronym (or possibly initialism) to remember whenever you want to know how strongly a given substance desires to kill you is "MSDS", for Material Safety Data Sheet. You can find an MSDS for just about anything, provided you know the name of the substance in question. You usually don't need to know the exact chemical name, either; brand names, especially of pharmaceuticals, often work.

One popular substance can have a large number of MSDSes for it, sometimes with different data, because, for instance, a product sold under the same name by different companies may be made with different constituents. MSDSes may also differ even when they're talking about the exact same substance, because different manufacturers and importers and so on may have different testing regimes, or may just plain get stuff wrong. Generally speaking, though, you can trust MSDSes, even if you can't find one for the exact brand of, in this case, cyanoacrylate (which is known to the relevant chemists, and many hobbyists, as "CA") you're worried about.

When I say "just about anything" above, I mean it. Here's an MSDS (in PDF format, like most online MSDSes these days), for skim milk. Including rather excessive first aid procedures to employ in case the substance is ingested.

Here's one, and another, for olive oil. More over-enthusiastic warnings; apparently you're not meant to allow olive oil to make direct contact with the skin. MSDSes for innocuous substances are often like this, possibly for reasons having to do with the covering of arses, or perhaps because there was no "zero hazard" box for the MSDS-maker to tick.

"Portland cement should not be eaten." Don't eat talcum powder, either. Molasses isn't very worrying, as long as there's not too much of it.

OK, enough silliness. Search for MSDSes for cyanoacrylate, plus a common brand name or two like "Krazy Glue", and you'll get hits like this, this, this and this. Here's a whole page of MSDSes for Loctite products, including various other glues and threadlocks. There's a "safety" section in the Wikipedia article for CA, too, plus some MSDS links at the end.

What all of these agree on is that CA products of various kinds, from the water-thin stuff used to wick into gaps in plastic models through to various non-runny gel-type versions, are not nearly as poisonous as you'd think from their alarming "chemical" odour. The fumes are an eye and mucous-membrane irritant, and if you're sticking a whole room worth of furniture to the ceiling as they did on MythBusters then you'd be nuts not to wear some kind of breathing protection, but this stuff really isn't that bad. I don't think it even releases much in the way of horrifyingly deadly gases if you burn it, though again, this is not recommended.

(With regard to the title of this post, glues that people sniff to get high in a rather dangerous manner are generally based on some kind of solvent with psychoactive effects, though usually not effects that people living a life somewhere above rock bottom would consider worth the damage. Glues with no such solvent, like CA, PVA, hide glue or epoxy, often aren't particularly bad to inhale, which is just as well since they won't even get you high.)

Part of the reason why superglue isn't very poisonous is that its "set" state, a hard polymerised lump, isn't toxic. It's still listed as an "eye irritant" when hardened, but only in the way that sand is. And CA really wants to polymerise. All actual CA glue contains "inhibitor" chemicals in addition to the CA itself, to stop the stuff from instantly turning into a lump of plastic in the bottle. Several common compounds in the world, chief among them water, will "kick" CA into polymerising. And since your eyes and mucous membranes and so on are all rather damp, any CA vapour that hits them polymerises instantly.

Now, this is still not a good situation, since having a very thin layer of plastic accumulate inside your nose and on your eyeballs is not most people's idea of a good time, but the body can deal with tiny amounts of the stuff with no trouble. (This also means that all you probably need as the abovementioned "breathing protection" is a damp cloth tied around your face.)

You can take advantage of the effect water has on CA to accelerate its bonding, by for instance breathing heavily on the two pieces of something you're gluing before bringing them together, or even by spitting on the glue, in extremis. That won't give you a very good bond, but if you're in a hurry, it'll do. You can also sprinkle bicarbonate of soda on the glue, or dribble CA onto bicarb, to get an instantly set, hard but brittle filler material. (It's basically Bondo for plastic spaceships.)

There are also liquids, known as "CA accelerators" or "kickers", that give you an almost instant full-strength bond when they touch CA. You generally put glue on one piece, a spritz of accelerator on the other, then bring them together and zap, instant gluing of two parts that you didn't quite bring together straight, god damn it.

(The accelerators, needless to say, have their own MSDSes.)

I'm not sure how much variation there is between the different accelerators; these days I just buy whatever's cheapest on eBay. Note that CA accelerator tends to be rather volatile and thus prone to liberate itself from the spray-bottle faster than many people can use the stuff. I recommend you keep the sprayer in a Ziploc bag.

The fact that there are substances that kick CA better than water does is the base for products like the one described in this MSDS, which is for a CA formulation used for fingerprint "fuming". You can do this neat little science trick with any CA, not just special expensive law-enforcement CA:

One thing hobbyists discover pretty quickly about CA, especially if they're using accelerator as well, is that the polymerisation process is exothermic. The glue gets warm as it polymerises, the increased temperature speeds up the polymerisation, and with enough glue and enough accelerator (or just CA by itself, if it's on something with a lot of surface area - cotton is particularly bad) the result is boiling polymerising CA. I don't trust any hobbyist who hasn't emptied five whole dollars worth of discount-store superglue into a very disposable container in the back garden, then added some generous squirts of accelerator, and stood well back.

This is another CA hazard. If you spill a lot of it on your cotton-denim jeans (or somehow just manage to deliberately use an unusually large amount), the profoundly crappy time you'd reasonably expect to have in your immediate future may be made significantly crappier by some nasty burns.

Anybody who's ever used superglue will have stuck the wrong things together, though with any luck just one finger to another, not a square foot of garment to singed flesh. If possible, a good way to remove CA is mechanically, with sandpaper or a file or, for many glue-on-skin situations, a disposable razor. (Or you can just wait; as the outer layer of your skin naturally flakes off, the glue will go with it.)

CA can also be dissolved with acetone, but the MSDSes for acetone are rather more alarming than those for CA. There are less toxic glue debonders out there too; again, please accept my very personal recommendation of whatever's cheapest on eBay and isn't just acetone.

(CA is also not just kicked into polymerisation by water, but also slightly soluble in it. So a long hot bath or shower may help you out, provided you have enough un-stuck limbs to be able to operate the taps.)

While I'm giving unrequested buying advice, as far as CA itself goes, I just buy it from discount shops. Given CA's irritating propensity to go hard in the bottle, I like the few-dollar cardboard oblongs with multiple little separately-bubble-packed tubes, the more and the smaller the better. Unless you've got an ongoing meaningful relationship with a local hobby shop - which I recommend; it's worth paying a bit extra for stuff if wise counsel on various subjects, or just hours of entertaining chat, is available in return - I see no reason to buy fancy brand-name CA for almost any job.

Getting back to that alarming cyano group which is indeed hanging off the few different, but effectively almost identical, kinds of CA molecule, it is in this case not much to worry about, but certainly is if it's hanging off something less complex, like a potassium or hydrogen atom. I find the lethality of various cyanide compounds almost amusing, since it's yet another sign of the absence of "intelligent design" of even this one planet, let alone the whole universe.

I mean, what's the element that's the basis of all life on this planet? Carbon. What makes up 78% of the planet's atmosphere? Nitrogen. (Don't miss this sample!) What do you get when the two of them get together? Cyanide, a deadly poison. It's sort of the opposite of the sodium-plus-chlorine thing.

And while I'm rabbiting on, I was also amused by MythBusters' and/or Discovery Channel's determination to call the glue they were using "super adhesive", a term that doesn't really exist in nature, to the point where a couple of slip-ups when someone said "superglue" anyway made it to air. This is in line with MythBusters' general self-censorship policy, in which no brands not integral to the myth are blurred or taped over or covered with new labels reminiscent of Repo Man.

Sometimes this policy seems to make little sense, though. In a recent special episode, MythBusters shot a .50 AE round from a Desert Eagle into watermelons, and they called the gun a Desert Eagle, even though there are various other firearms that chamber that round. But in the episode a while back where they demonstrated what a bad idea it is to wrap your hand around the cylinder of a .50 Smith & Wesson revolver when firing it, not one mention was there of the brand of that gun, though anybody familiar with the preposterous hand-cannon arms race of recent years could have mistaken a S&W Model 500 for anything else.

(If you haven't been watching the nutty progression of ever-more-wrist-smashingly-powerful handgun cartridges and the you've-gotta-be-kidding-me guns that shoot them, compared to which the action-movie-staple .50 AE Desert Eagle's .44-Magnum-ish bullet energy looks positively feeble, then you could be forgiven for thinking a short-barreled Model 500 was some kind of flare gun. I wonder if even this has been surpassed by now?)

The "super adhesive" thing is particularly nutty, though, since they could have just called it cyanoacrylate.

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

14 Responses to “Sniffing glue”

  1. havoc10mm Says:

    Seeing as I rather enjoy the wrist-breaker arms race (being a 'Mercun, do I have a choice?)...

    Depends on how you define "surpassed."

    Still bigger.

    All comfortably exceed 12ga and .500S&W in most ballistic measures. .50BMG is a perverse choice for a handgun of course, for several reasons. If one can call a five-and-a-half kilo lump of steel a handgun.

    But for sheer carpus fracturing capability, it's most unwise to wager against this.

    • dan Says:

      That Nitro Express revolver is very much a modern "howdah pistol", which according to many people who encountered one was indeed an excellent device with which to protect oneself from a tiger that had suddenly joined one on top of one's elephant, provided one did so by handing the pistol to the tiger and encouraging him to fire it.

      If one can call a five-and-a-half kilo lump of steel a handgun.

      Indeed. If you make a "pistol" that weighs more than a loaded M16 or AK-47, then unless the intended user is Hellboy, I think it's reasonable to say that the weapon is actually a "stupid-shaped rifle".

      • havoc10mm Says:

        That Nitro Express revolver is very much a modern "howdah pistol"

        I'm not sure that's really correct. Howdahs were designed to be handy. Most of the info I've been able scrounge up puts them in the 3 pound range, not 13. That .600 is almost strictly a novelty; I can't imagine someone even pretending it has any practical use. For that matter, 2oz. of bullet isn't terribly practical in a rifle...

        I would think this is on the right road, except it's not chambered for a rifle cartridge. Maybe?

  2. Fallingwater Says:

    Since we're talking about glues and such... would you happen to know if there's a glue that is non-toxic and capable of withstanding hot water vapour? I have a moka pot with a leaky coffee basket and I know nothing at all about welding aluminium (and I don't even have the gear)...

    • dan Says:

      There are a lot of epoxies, in particular, that're sold as food safe according to one interminable government standard or another. The catch there is that if you don't mix them perfectly - exactly the right ratio of resin to hardener - you'll have one or the other left over, which doesn't necessarily mean anything dangerous will leach into your food, but which may make stuff taste funny.

      If it were just me, I'd use metal-filled epoxy like the legendary Fixer Of All Things, Devcon, and not worry about it. But I am often an idiot.

  3. sig Says:

    To open a new superglue I had to puncture a metal "skin" under the cap. When I punctured it, I saw a tiny drop fly out... and straight into my right eye. It hit the white of my eye, but luckily there was not enough to glue my eye shut (or open).

    The glue was dried instantly, and stuck to my eye. Felt like sand.

    Found out only time would help, after a call to a doctor, another to a hotline for poisons, and googling (not fun with a VERY watery eye).

    I later learned caustic soda is really bad for eyes, and hurts more...

  4. snark_be Says:

    I've read at about someone using Krazy Glue for sealing a (voluntary inflicted) wound.

    Would that be dangerous if the chemicals enter your blood stream?

    • dan Says:

      Theoretically yes, since lumps of plastic are not meant to be in your blood, but in practice almost certainly no.

      It depends on the wound and the way the glue is applied, of course, but if you just cut yourself superficially and squirted glue into the wound at random, it'd set when it hit the blood, and basically just stay where you put it. Only a quite serious wound offers access to major vessels able to carry things away.

      There's an urban myth that superglue was used first as a way to seal battlefield wounds, but there are, today, surgical cyanoacrylate compounds, and countless people (including a lot of modelers who dropped a hobby knife on their foot...) have used commercial superglue to pin shut a small cut.

    • Mayhem Says:

      Cyanoacrylate has been used for wound care for a very long time, going back to Vietnam. These days for people they tend to use a particular medical formulation of 2-octyl cyanoacrylate as it is less irritating than the cheaper forms, but vets will use whatever is handy. None are particularly toxic though for the reasons listed above - the compound polymerises very fast with water, which blood contains a lot of, and at the end of the day, you aren't using very much, and the excess wells up out of the wound.

      • TwoHedWlf Says:

        And you're not really supposed to be putting it IN the wound. You pinch the cut shut and put the CA over the top to hold it.

        • dan Says:

          There's some confusion over exactly what cyanoacrylate was used for in Vietnam. It was a spray product, for a start, and many sources say it was used to "stop bleeding", which is not the same thing as tacking a cut closed. I wouldn't be surprised if its principal use was as more of an "instant dressing" - spray it all over the mess some shrapnel has made of a guy's torso, it hardens pretty much instantly, and all of the little holes are plugged. Won't do much to stop internal bleeding, of course, but with any luck it'll keep the guy going until the real doctors can see him.

          Today, there are several medical and veterinary CAs that're used for several tasks, including in place of sutures for wound closure. People may have used it that way in Vietnam, too, but I don't know.

          (And the legend that CA was invented for wound care is, of course, wrong.)

          Demonstrably, household CA works fine to close superficial "Band-Aid" wounds, and can be more effective at stopping bleeding. The classic example, again, is the modeler whose X-Acto knife rolls off the table and lands on his foot, and he picks it up and keeps building a plastic Spitfire, only to notice five minutes later that he now has one white sneaker and one red one. CA will probably do a better job of closing that sort of annoying but not at all life-threatening puncture wound than any other supermarket first-aid product. This is no doubt what led to today's over-the-counter CA-based "liquid bandage" products.

          • TwoHedWlf Says:

            In Vietnam CA was used as a spray by medics, this increased the odds of survival for the first patient, but wasn't so effective in cases of multiple wounded soldiers. The medic usually had great difficulty treating others with his hand superglued to the first patient... :P

  5. El Mariachi Says:

    The reader should ascertain whether her son is actually using CA to build his model planes. When I was a boy, the airplane glue I used (Testors) was toluene-based and most definitely toxic. Of course this was in the 70s and early 80s, when child safety didn’t seem to be as much of a concern as it is today; they may not even sell the toluene stuff any more.

  6. asdfTIMESfive Says:

    Was the comment about cyanide and intelligent design sarcasm or serious? I always viewed these types of Easter eggs as facetious.

    Either way, tell more more I might have overlooked!

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